Electric lamp socket



Sept. 20, 1932. G. H. E'LWELL ELECTRIC LAMP SOCKET Filed Oct. 10. 1927Patented Sept. 20, I932 UNITED STATES enonen HENRY ELWELL, on NEW HAVEN,CONNECTICUT, AssIeNon To THE ennis'r MANUFACTURING COMPANY, on NEW HAVECONNECTICUT, a eonrona'rIo or CONNECTICUT ELECTRIC LAMP soonerApplication filed October 10, 1927. Serial 110.225.192. I I

The. invention relates to improvements in electric lamp socketsadaptedto receive an incandescent lamp bulb and to lock the same thereinagainst theft. The art discloses variedforms of theft proof electriclamp sockets of which many require some special constructionof the metalbase of the lamp bulb, or the breaking of the lamprbulb upon itsremoval, but "the invention herein disclosed adapts the improved lampsocket to receive and to locktherein the ordinary incandescent lamp bulbreleasable .only under certain conditions. The applicant is also awarethat improvements in the art have already extended to electric lampsockets of this character which include either a rotatable screw-shelladapted to be locked against rotation upon the authorized placing andremoval of the lampjbulb, or a locking band or cover with an inturnedflange to lockingly engage with the annular edge of the metal base ofthe lamp bulb. The rotatable screw-shell'and the locking band both havetheir advantages, and it is the intention of this invention to. soemploy principles suggested, perhaps, by each in the new construction ofa novel theftproof electric lamp socket that will further develop theart in that direction, and therefore the objects of the invention are toprovide an'electric lamp socket carrying a rotatable member adapted tolockingly engage the annular edge of the metal base of an ordinaryelectric lamp bulb and rotat'etherewith until the bulb is fully in placewithin the screw-shell contact and then automatically become lockedagainst reversed rotation; and to provide for the removal of the bulbonly when the electric circuit embracing the particular fixture isopened by means of the throwing off the circuit switch.

The following is the description of an embodiment of the invention theconstruction of which may be varied within the scope of what mayhereinafter be claimed without a departing from the spirit or modifyingany of'the advantages of the invention. Reference being hadto theaccompanying drawing one sheet) the Figure 1 is an upright elevation ofan improved-socket without a casing,but witha metal base of an electriclamp bulbi'lo'cked thereto; Figure 2 is "a v similaru'priglrtelevationbutin a different rotary position and including the. insulation" liningillustrated incross-section; Figured is an upright elevationofthe'screw-shell'and rotatable memberin. assoclated relatlon; and

Figure 4 is a cross-sectional view of the socket at the line 44 p ofFigure 1',' 1ll ustrat1 'ng the rotatable member unlocking means.

Referring more particularly'to the drawing, in which similar parts aresimilarly numbered', thescrew-shell 1 is fixed to the 'body ofinsulationQ in any desired manner;- The rotatable locking member Sisofsuch'screwshell'formation as to ads; t it for meshins its rolled-inthread with the exterior presentation of the rolled-in thread of thescrew-shell j 1, as bestillustrated byfFigure 3. The inner extremity ofthe rotatable locking member 3 is provided with an unthreaded annularportion 4 carrying the spring arm 5 inwardly"- presenting the catch 6for locking engagement wlth an edge 7 bounding an openlng -8 in anunthreaded portion 9 of the sorew shell 1. This opening 8 ordinarilyexists in screw a shell formation already known to the art, but ifdesired a special opening8inay be provided for the purpose aboveexplained.- The outer extremity of the rotatable lockingmem ber 3 is soconstructed as-to' assume the'form 0f a-series of spring arms,preferably more than two, each arm presenting an inturned flange portion10, as best illustrated by Figi ure 3, for locking engagement with theannular edge 11 of the metal base 12 of anordinary incandescent lamp,asillustrated inFig I ures 1 and 2. The unthreaded portion'4 of therotatable memberis provided, substantially diametrically opposite thecatch 6 and the edge 7 in'locked relation, with a small elongatedperforation 13; A similar perforation in the unthreaded portion 9 of thescrew-shell is made unnecessary bythe usual opening thereincorresponding with and located opposite the opening 8 and extendingsufliciently tobe used as illustrated by Fig 'ure '4 and as laterexplained The floor 14 of the lamp receiving socket to whichthe shell 1is rigidlysecured'isiprovidedwithithe guide 1.5 to positively direct thecourse of a needle 16 inserted within the perforation 18, and aconvenient way in which to construct this guide is by rolling it up outof the screw-shell bottom as illustrated by Figure 4. The course of theneedle 16 as directed by the guide 15,'an integralpart of thescrew-shell 1, insuresthe "engagement of the needle with the contact 17an integral part of the switch.

contact bar 21 depending therefrom, the otherswitch bar 19"depe'ndingfromthe cen-' ter 'cohta'ct"20 andbeingparallel-to and in spacedrelation with the switch contact bar 21, as illustrated in dotted lineby the Figure 1, and the catch 6 inlocked postion.. It is obvious thatwhen the rotatable member 3 is 1'0- tated upon the screw-shell to adegree greater than-is illustrated by'TFigure 3 the lamp bulb.

maybe insertedtherein so that the 'inturned flange portion '10:mayengage the edge '11 of; the 'metallamp g'bZtSQ 1-2. ,The bulb may bescrewedintoythe screw-shell as the rotatable member; is turnedtherewithfirst by the hand andathen'icarried by th'e gripfl'ofv the spring armsaround-the annular edgev 11 until the lamp is electrically connected andthe spring catch 6 falls over the edge-7;;as' illustrated by Figure 1; VThe lamp 1 bulb? thereby becomes automatically locked within theelectric lamp socket for any attemptedunauthorized removal thereofis-pre'vented by the flange por-.

tions '10 blockin'gthe displacement of the annularedge-l ltof the lampbase'andithe inability of the rotatable.lockingmember 3 to turn with thebulb byreason? ofvits locked condi-' tion with the screw-shell as aboveexplained. Anyfimanipulation ofuthe flanges in an attempt to release thelamp bulb is frustrated by the fact that these spring arms 5 areprotected by the snu girelatio'n thereto of theinshlationsleeve-18-illustrated by the Figure 2, associated: with theelectric lamp socket in a manner well-known to'the art}; The electriccircuit" switch, controlling the fixtures from thecatch-6,enabling thepushing of the spring arm- 5" sufliciently' to disengage the catch 6from the edge 7 while a reversed rotation of the lamp bulb carrying therotatable member thus freed is. then limited only by the needle 16within the elongated perforation 13. The needle mayiimmediately' bewithdrawn; for the continued -rotati"on ofthe lamp bulb carries th'erotatable member 3- With its catch 6,

thef latteri immediately" riding out of the plane of the opening-8. With"the switch boardi locked up within an enclosure or lo- ,catedfzinmenu-0a place'iand therefore not readilyaccessible to the unauthorizedperson it makes it difficult, if not impossible, for an electric lampbulb to be wrongfully removed; for any attempt to remove a lamp bulblocked within this improved socket without first having thrown off thegeneral switch would endangerthe manipulator should'hethrust a needleinto the perforation 13 while'the'screwshell and the center lamp contactare electri cally alive. By providin with which to release" the catch j6, substitute of insulation material, such'as a toothpick, can'be-e'mployed to defeat the purpose of this' invention.

What'I claimi's:' 1.;An electric lamp socket comprisingt a a h id 15 or.the entrance therein of a fragile steel needle screw-shellto receivethe. threaded base ofa lamp, a second-screw shell threaded upon saidfirst shelland 'carrying'flanged portions for holding. engagements withan annularedge of the threaded base, and means providedby reverserotationq both shells toflock the shells against relative I 2; Anelectric lamp .socket comprising, a

screw-"shelllto receive the threaded base of a lamp,-said shellhaving anopening-in its cylindrical wall,v and a second screw-shell with anannular edge o-ftthe lamp base, and'a threaded uponvthe firsti-shell andcarrying flanged portions for holding(engagements.

catchnmember. carried by thesecond shell for f engagement within theopening to: lock the shells'against reverse rotation.

3. An electric lamp socket comprising a 7' screw-shellto receiveithethreaded base. of a lamp,-said shell havingoppositely positionedopenings' in its cylindrical wall, a second screw-shellthreaded uponthefirst shellx and t carrying 'flanged'portions for holding engagementswith an annular edge ofthe lamp,

base,- a catch memberpcarried by the second shell-for engagement withinone of the openingstolocktheshells against'relativereverse :rotation,and; means provided vby the socketto safely dislodgewthe catch memberelectric-current cut off. i

4. electric lamp socket comprising a screw shell for'rec'eiving thethreaded metal 1 base-ofza lamp-ya sleeve of insulation surv from itslocking' engagement only with the rounding said-screw-shell', thescrew-shell having oppositely positioned openings in its cylindricalwall; contacts within tl'lB Sl'l8ll I and insulated one from the otherand from the shell, each contact having afixed depending switchbar; aguide having apassage therethroughprovidedfbythe shell,-the passagebeingzaligned with one-of the contacts; a

second screw-shell threaded' upon the first shell, the secondshellhaving an elongated opening in its cylindrical 'with ascrew-shellopening; flanged portions wall toregister I integrallyprovided by the second shellforholding engagements'with an annular edgeI Of an inserted metal baseof a lamp, thesleeve it? i of insulationco-operating to maintain the holding engagements; a catch member carriedby the second shell for engagement within one of the openings of thefirst shell to lock the shells against relative reverse rotation; andmeans to safely dislodge the catch from its engagement with the openingonly with the electric current cut oil, said means comprising a fragileneedle adapted for entrance within openings of the second and firstshells and into the guide passage to bethereby directed to and contactedwith one of the contacts to establish between the shells and suchcontact a short circuit, the shells and such contact being Within theelectrical circuit.

GEORGE HENRY ELWELL.

